Hypervelocity gun having a hydraulic stage for velocity conversion



Sept. 23, 196% J. F. CHARPENTIER 3,468,216

HYFERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION 4Sheets-Sheet 1 Filed May 13. 1968 eirl - J WHMHWVL Q n E INVENTOR JEANF. CHARPENTIER ATTORNEYS p 23, 1969 J. F. CH PENTIER 3,468,216

TY GUN HAV HYFERVELOCI A HYDRAULIC STAGE FOR VELOCITY CONVERSION FiledMay 13. 1963 4 Sheets-Sheet Z INVENTOR JEAN F. CHARPENTIER Sept. 23, N69J. F. CHARPENTIER 3,468,216

HYPERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION FiledMay 13, 1968 4 Sheets-Sheet 5 |NVENTOR JEAN F. CHARPENTIER awmwzwATTORNEYS Sept. 23, 1969 J. F. CHARPENTIER HYFERVELOCITY GUN HAVING AHYDRAULIC STAGE FOR VELOCITY CONVERSION 4 Sheets-Sheet 4 Filed May 13,1968 2% ivy m INVENTOR JEAN F CHARPENTIER ATTORNEYS 3,468,216HYPERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION JeanF. Charpentier, Akron, Ohio, assignor to Goodyear Aerospace Corporation,Akron, Ohio, a corporation of Delaware Filed May 13, 1968, Ser. No.728,665 Int. Cl. F41f 1/00 US. Cl. 89-8 Claims ABSTRACT OF THEDISCLOSURE This invention relates to a high velocity gun utilizing ahydraulic accelerator stage which converts the limited velocitytransmitted by a heavy large caliber projectile into a hypervelocitymotion transmitted to a light subprojectile.

In todays space-age, in order to simulate speeding micrometeorites, ithas become necessary to develop guns that will shoot tiny projectiles atextremely high velocities. Many efforts have been made along these linesusing various mechanical and electrical principles. However, none ofthese prior art devices have been able to obtain the velocities desired,nor have they been as simple and inexpensive as desirable. Further, noneof these prior art devices have been suitable for incorporation tolarger caliber projectiles.

Therefore, it is the general object of the present invention to providean improved high velocity gun which has great efficiency, and which isrelatively low in cost.

A further object of the invention is to provide a gun for providing anextremely high velocity to a light subprojectile by transmitting theforce from the explosive firing of a heavy large caliber projectile tothe light sub projectile by a hydraulic accelerator stage.

A further object of the invention is to provide a high velocity gunwhich utilizes a hydraulic accelerator stage operating through a changeof fluid volume configuration to which only the opposing forces ofinertia and viscosity cause energy loss to thereby maximize themagnitude of the energy transmitted from the explosive acceleration of aheavy large caliber projectile to a light subprojectile.

The aforesaid objects of the invention and other objects which willbecome apparent as the description proceeds are achieved by providing ina high velocity gun the combination of an elongated barrel having auniform diameter bore from one end through most of the length thereof,but a reduced diameter bore coaxially aligned with and extending fromthe other end to the uniform diameter bore, a piston slidably receivedin the uniform diameter bore, means to propel the piston down theuniform diameter bore, a non-explosive liquid carried by the piston inthe end thereof nearest the reduced diameter bore, and a pellet ofsubstantially the same diameter as the reduced diameter bore carried bythe piston in such a manner whereby the kinetic energy of the propelledpiston is transferred to the liquid when the piston reaches the reduceddiameter bore, and the liquid transfers the kinetic energy to the pelletcausing it to be expelled from the end of the reduced diameter bore.

For a better understanding of the invention, reference should be had tothe accompanying drawings, wherein:

FIG. 1 is a side elevation showing the shape and configuration of theentire gun;

FIG. 2 is an enlarged cross-sectional view of the muzzle andillustrating the relationship between the large diameter bore and thereduced diameter bore, as well as the piston ejecting mechanism;

3,468,2l6 Patented Sept. 23, 1969 FIG. 3 is an enlarged cross-sectionalview similar to FIG. 2 except illustrating how the piston ejectingmechanism functions;

FIG. 4 is a vertical cross-sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a vertical cross-sectional view taken on line 5-5 of FIG. 2;

FIG. 6 is a vertical cross-sectional view taken on line 6-6 of FIG. 2;

FIG. 7 is an enlarged cross-sectional broken-away illustration of thepiston and hydraulic energy transfer characteristics as the pistonapproaches engagement with the reduced diameter bore;

FIGS. 7A, 7B, and 7C are transverse cross-sectional views taken onrespective lines along the length of the piston of FIG. 7 to better showthe configuration thereof;

FIG. 8 is an enlarged cross-sectional broken-away view of the piston aninstant after it has engaged the reduced diameter bore showing theexpansion of the hydraulic fluid1 to cause final acceleration to thepellet or sub-projecti e;

FIG. 8A is a transverse cross-sectional view of the subprojectile takenon line 8A8A of FIG. 8;

FIG. 9 is an enlarged cross-sectional broken away illustration of thepellet or subprojectile as it is finally discharged from the muzzle ofthe gun, particularly showing the discharge of the hydraulic fluidtherefrom;

FIGS. 9A, 9B, and 9C are transverse cross-sectional views taken onrespective lines along the length of the compressed piston of FIG. 9 toshow the configuration thereof;

FIG. 10 is an enlarged cross-sectional broken away view of the explosivepropellent which is used to accelerate the piston from the breach end ofthe gun; and

FIG. 11 is an enlarged view showing the configuration of thesubprojectile.

While the gun of the invention may be used for the acceleration of anyprojectiles, and for any type of use, it was primarily designed foraccelerating small projectiles to simulate micro-meteorites in flight,and hence it has been so illustrated and will be so described. However,it should be understood that the gun clearly could be used to acceleratearmor piercing projectiles, or for any other suitable application.

With referece to the form of the invention illustrated in FIGS. 1through 3 of the drawings, the gun is illustrated generally by numeral10 and comprises the alignment of two barrels having bores of differentcalibers. Specifically, there is a discharge barrel 12, and a breachbarrel 14. The discharge barrel 12 is positioned by any suitable means.In essence, the breach barrel 14 includes a uniform diameter bore 16extending substantially the full length thereof, while the muzzle barrel12 has a reduced diameter bore 18 at its discharge end and an enlargedbore in which the breach barrel 14 is received.

The breach barrel 14 and muzzle barrel 12 are slidably interlocked inlimited movement in both directions by a raised annular ring 16A onbreach 14, and two inwardly extending flanges 18A and 18B on the muzzlebarrel 12, as clearly shown in FIG. 2. In order to maintain both barrelsat the desired extended relationship to each other, a plurality ofdouble wound helical springs 20, or equivalent means, are positionedbetween the flanges 16A and 18B, as most clearly shown in FIGS. 2 and 6.

The breach barrel 14 has an extending lip portion 22 which is adapted toact both as a stop for a projectile 24, and a projectile dischargemechanism, as will be more fully described hereinafter. The exactconfiguration of the extending lip 22 is more clearly seen in FIG. 4.The muzzle barrel 12 has a slotted cutout portion 26 extending partiallyaround the circumference in proximity to the bore 16 in breach barrel14, whereby the projectile 24 can be ejected, as is more clearly shownin FIG. 3, and will be more fully explained hereinafter. A gas passage28 extends from behind the lip 22 through the breach barrel 14 to apoint lying between the flanges 16A and 18A, as best seen in FIG. 2. Aprojectile discharging spring 30 also operatively extends through thelip 22 of breach barrel 14 to act in ejecting the projectile 24, as moreclearly shown in FIG. 3, and defined in more detail hereinafter. FIG.rather clearly shows the projectile discharge opening 26, the gaspassage 28, and the relationship of the muzzle barrel 12 relative to thebreach barrel 14.

In association with the apparatus of the gun as shown and described inreference to FIGS. 1-6 the construction of the projectile 24 is quitecritical to the proper operation of the apparatus. Specifically, theprojectile and its operation in the gun is more clearly illustrated withreference to FIGS. 7, 8, and 9 and associated transverse cross-sectional views.

The projectile or piston 24 comprises an outer housing or shell 40 whichis made for a suitable plastic that can be readily formed to a desiredaccordion type shape in cross-section as shown in FIG. 7B and beextensible or moldable without failure under the force of impact whichimparts the projecting force to the subprojectile. The base of shell 40is formed with a raised annular flange 42 which provides sealingengagement with the bore 16. A tapered liquid ejector 44 is centrallypositioned within the shell 40. This is preferably a metal rod and isinterlocked with the shell by threadably receiving a locking cap 46 inthe enlarged end thereof which effects a clamp ing action onto an innerlip 48 preferably formed as an integral molded part of the shell 40. Asubprojectile indicated generally by numeral 50 comprises a plastic body52 and a weighted metal nose 54, as best seen in FIG. 8. The innercentral portion of the body 52 is formed with a somewhat sphericallyshaped recess 56 which snaps with a force fitted engagement over anenlarged ball end 45 of the ejector 44, thus holding the subprojectile50 in position with respect to the shell 40. However, the skirt portionof the subprojectile 50 is also sealed to the shell 40 at a yieldingbase line 53 to provide a hydraulic seal before the firing of the piston24.

The energy transferring objects of the invention are achieved byproviding a hydraulic fluid in the open or hollow area between the shell40 and ejector 44, this fluid being indicated by numeral 60. The fluidmust be a nonexplosive substantially non-compressible hydraulic liquidsuch as water or glycol.

In essence, the invention contemplates that suitable means are providedto accelerate the entire projectile 24 under great speed down the largeuniform diameter bore 16. The invention contemplates a suitableexplosive charge for this purpose. For example, the inventionillustrates in FIG. an explosive charge indicated generally by numeral61 which has specific contours in spaced relation so as to give amaximum and uniform propelling explosive force thus giving theprojectile 24 the greastest possible speed down the bore 16. A breachblock 63 pivotally mounted to the end of the breach barrel 14 allowspositioning of the charge 61, and directs the force thereof down thebore 16. In essence, the charge 61 is designed to provide an explosiveunlimited mass which is able to burn within a time interval as small aspossible.

Specifically, the explosive charge 61 constitutes successive layers ofthree different types of explosive materials distributed transverselyand longitudinally along a curved medium profile with the center ofcurvatures of each successive layer located towards the muzzle of thegun. The explosives consist of an igniter 62 which acts as a fuse, andrepresents a very thin layer. Next is a primer explosive 64 whichconstitutes a small area adjacent on both sides of the layer of igniter62. And lastly, is the bulk of the explosive charge 61 which comprises apropellant 66 which lies between the adjacent layers of the primerexplosive 64. The entire explosive charge 61 is normally encased in asuitable metal shell 67. The mass of the explosive charge 61 is ignitedfrom the front face, or in other words the face adjacent the base of theprojectile 24 by a suitable electric igniter 68 connected through thehousing or case 67 and to the central point of the fuse igniter 62.

Through the structured arrangement of the layers in the explosive theignition progresses in a three dimensional process and the timing isobtained by selecting the number and thickness of the layers of thedifferent explosives. The volume or cross sectional area of theexplosive charge 61 and particularly the propellant 66 increases towardsthe rear of the breach in order to allow for a fast increase in theburning area. This is done to provide a burning mass rate as high asrequired to maintain a constant pressure application to the base of theprojectile as the latter travels towards the muzzle through the bore 16.Normally, in most explosive propellant charges, the burning rate isuniform, and of the same cross section throughout its length so that ineffect the pressure behind the projectile decreases as it moves down themuzzle.

FIGS. 7, 8, and 9 illustrate in sequence the impacting of the projectile24 into the reduced diameter bore 18 in the muzzle barrel 12 of the gun10 after its acceleration down the bore 16 by the explosive charge 61.Essentially, the high kinetic energy imparted by the explosive charge tothe piston 24 in transmitting it down the bore causes the integral outershell 40 which is formed with the accordion folds shown in FIGS. 7B and7C to be compressed over the ejector 44 when the outer shell 40 contactsthe tapered mating surfaces at the end of the inner bore 18. FIGS. 9Band 9C illustrate the compressed relation of shell 48 over the ejector44. This causes high compressive pressure to be exerted upon thehydraulic layer 60 and since the layer 60 is essentiallynon-compressible the pressure is relieved by forcing the subprojectile50 to pop off the ball end of ejector 44 and out and down through theinner bore 18, as clearly shown in FIG. 8. FIG. 9 illustrates thecomplete compression of the outer shell 40 over the ejector 44 whichcauses just enough fluid displacement to force the subprojectile 50completely to the end of bore 18.

The end of the bore 18 is reduced in diameter such that thesubprojectile 50 is lodged at the end of the bore, at the same time thefinal stage projectile pellet 54 is ejected at high velocity. In orderthat the hydraulic fluid utilized to propel the subprojectile 50 downthe bore 18 does not rupture the muzzle, the invention contemplates thatliquid discharge ports 57 are positioned around the bore 18 to providethe pressure relief and discharge of the liquid as shown in FIG. 9.v

Another method of exiting the projectile is shown in FIG. 11 wherein thefinal stage projectile is also the subprojectile 50. The end of themuzzle bore 18a is shaped to fold back the skirt 52 of the subprojectile50 to an inflight aerodynamic shape. The subprojectile is expelled fromthe muzzle along with the fluid as shown in FIG. 11. In this variation,no exit ports 57 are needed as the fluid exiting with the subprojectileprovides aerodynamic stability to the projectile. However, exit ports57a are provided in the subprojectile skirt 52 to relieve the fluidpressure when the skirt 52 is drawn back to form the teardrop shapeshown in FIG. 11. The shape of the front end of the muzzle is changed toprovide an airstream contour 56 which will not impede the velocity oraerodynamic stability of the subprojectile 50.

The invention contemplates that the outer shell 40 and the ejector 44and cap 46 will comprise approximately to of the complete weight of theprojectile 24. This portion of the projectile acts as an accumulator ofkinetic energy. The second stage of the projectile essentially comprisesthe liquid or hydraulic mass or layer 60 which is a receptor-transmitterof kinetic energy. Its function consists of transferring, with a highefficiency, the energy from the outer shell and ejector to the solidthird and final stage comprising the subprojectile 50. The hydraulicmass or layer 60 will weight between 10 to 15% of the completeprojectile weight, and will always constitute sufiicient volume tocompletely push the member 50 down the entire length of bore 18. Thesubprojectile 50 Weights approximately of the complete projectileweight.

With reference to FIGS. 2 and 3 of the drawings, the operation of thegun to eject the projectile 24 after the subprojectile 50 has beendischarged will be described. Specifically, the hot gases of combustionutilized to propel the projectile 24 down the bore 16 enter through theport 28 and are deposited thereby between the flange 16A and 18A. Thispressure thus causes a spreading between barrels 12 and 14 which allowsthe projecting finger or arm 22 to draw the projectile 24 back out ofits seated position into the reduced diameter portion of bore 18. Thegas pressure operates against the springs 20, but is suflicient toovercome the force of such springs. The rapidly applied high pressure ofthe gas causes substantially equal and opposite movement of each barrel12 and 14 to a position indicated in FIG. 3 until the spring 30 bottomsagainst flange 18a causing it to discharge the projectile 24 out theport 26. At the same time, all gas pressure is exhausted from the bore16 through the opening 26, and with this pressure relieved, the springs20 force the barrels back to their original position shown in FIG. 2.If, however, some catch means are associated with the recoil, the barrel12 and 14 can be held in the position shown in FIG. 3. This may bedesirable to allow any type of cleaning probe or other mechanism todischarge the member 54 from its wedged position in bore 18. However,the invention contemplates that if suitable ablative material is usedfor member 54, it will burn up from the hot gases of combustionimpinging thereon when the projectile 24 is discharged.

It is found that this particular method of transferring kinetic energyfrom a large mass to a small mass through a liquid medium has greatefliciency. In fact, the loss of kinetic energy is normally less thanabout 5 percent, and extremely high muzzle velocities for the reducedsize projectile can be achieved. In fact, velocities much greater thanare available with any known gun today have been demonstrated asfeasible. In other words, the hydraulic accelerator stage or layeroperates through a change of fluid volume configuration to which itopposes only inertia and viscosity forces. The configuration conversionis independent of all wave formations and motion which may happen withinthe fluid. It has been found that the loss of efliciency due to fluidelasticity, if water or glycol are used as the hydraulic layer, is amaximum of only about 4 percent of the volume.

While in accordance with the patent statutes only one best knownembodiment of the invention has been illustrated and described indetail, it i to be particularly understood that the invention is notlimited thereto or thereby, but that the inventive scope is defined inthe appended claims.

What is claimed is:

1. In a high velocity gun the combination of an elongated barrel havinga uniform diameter bore from one end through most of the length thereof,but a reduced diameter bore coaxially aligned with and extending fromthe other end to the uniform diameter bore,

a piston slidably received in the uniform diameter bore,

means to propel the piston down the uniform diameter bore,

a non-explosive liquid carried by the piston in the end thereof nearestthe reduced diameter bore, and

a pellet of substantially the same diameter as the reduced diameter borecarried by the piston in such a manner whereby the kinetic energy of thepropelled piston is transferred to the liquid when the piston reachesthe reduced diameter bore, and the liquid transfers the kinetic energyto the pellet causing it to expelled from the end of the reduceddiameter bore.

2. In a high velocity gun the combination of an elongated gun barrelhaving a bore,

a piston slidably received in the bore from one end of the barrel,

means to limit the sliding movement of the piston in the bore towardsthe other end of the barrel,

means to propel the piston through the bore from said one end of thebarrel towards the other end,

a pellet slida-ble through the bore from the other end of the barrel,said pellet being much smaller in mass than the piston, and operativelycarried by said piston, and

non-explosive liquid means operatively carried by said piston toeffectively transfer the kinetic force of the piston to the pellet whenthe piston is limited in its propelled movement through the bore.

3. A combination according to claim 2 wherein explosive means areutilized to propel the piston down the bore, with such explosive meansproviding a constant pressure behind the piston as it translates downthe bore.

4. A combination according to claim 2 where the liquid is water.

5. A combination according to claim 2 where the liquid is glycol.

6. A combination according to claim 2 wherein there are liquiddispersion holes located around the muzzle of the bore to discharge theliquid means after an effective transfer of the kinetic energy of thepiston to the pellet.

7. A combination according to claim 2 where the bore includes aconversion breach which tapers from a constant large diameter to aconstant smaller diameter and wherein the piston consists of:

an appropriately shaped hollow first stage housing shell having a noseand a bottom made of any convenient material able to be squeezed withoutappreciable structural resistance,

a rigid structure internally extended from the bottom of the shell tothe apex of the nose, having a profile shape designed in connection withthat one of the conversion breach whereby, as the piston is propelledinto the conversion breach the housing shell is jammed between thestructure and the conversion breach,

a hydraulic liquid between the shell and the rigid structure, and

a subprojectile hydraulically sealed to the nose of the shell, butdesigned to break free and be propelled down the bore upon an increasein the hydraulic fluid pressure.

8. A combination according to claim 7 where the shell is provided withlongitudinally extending accordion folds to enhance its ability tocompress an elongate upon jamming between the conversion breach and thecomplementary rigid structure.

9. An apparatus according to claim 2 where the elongated gun barrelconsists of two sub-barrels interlocked in limited sliding relationshipto each other, and normally biased to one end of the limit, and whereone of the subbarrels has a piston discharge port whereby the hot gasesof combustion propelling the piston down the barrel effectively causesliding movement of the sub-barrels in a direction opposite to the biasto discharge the piston from the piston discharge port after the pistonhas transmitted its kinetic energy to the liquid means.

10. In a hypervelocity gun the combination of a first energizing gunhaving a constant caliber bore extended from the breach to the muzzleend, said muzzle end connected in a continuous manner with a conversionbreach and a second barrel extending from, and coaxially aligned withthe energizing gun barrel, said conversion breach and barrel having avariable decreasing bore caliber extending from said muzzle end to anappropriate distance where said caliber becomes constant, but smallcomparing to the caliber of the energizing gun barrel bore, a

compound multi-stage projectile slidably received in the uniform caliberbore, means to energize the compound multistage projectile inside theconstant caliber bore barrel, multistage projectile comprising a firststage which stores most of the energy provided by the energizing gun, anon-explosive liquid stage carried by the compound multistage projectileto the conversion breach, and a subprojectile carried by the compoundmulti-stage projectile in such a manner whereby the kinetic energy ofthe first stage accumulator is transferred to the liquid when thecompound projectile enters the conversion breach while the liquidtransfers the energy to the subprojectile causing it to be expelled withhigh velocity from the muzzle of the second gun barrel.

References Cited SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.

